双目立体视觉测量系统的设计与实现

依据双目立体视觉原理,对双目立体视觉测量系统的设计与实现展开研究,介绍了双目立体视觉测量系统的组成,对系统涉及的主要关键技术进行了详细的探讨。结合相关硬件设备,利用VC6．o和Matlab软件开发平台实现了双目立体视觉测量系统,经过实验验证该系统能够对运动物体的轴线三维姿态进行高精度的测量。     

多途信道短慕线时间反转聚焦研究(英文)

The existence of a multi-path channel under the water greatly decreases the accuracy of the short baseline positioning system.In this paper,the application of a time reversal mirror to the short baseline positioning system was investigated.The time reversal mirror technique allowed the acoustic signal to better focus in an unknown environment,which effectively reduced the expansion of multi-path acoustic signals as well as improved the signal focusing.The signal-to-noise ratio(SNR) of the time reversal operator greatly increased and could be obtained by ensonifying the water.The technique was less affected by the environment and therefore more applicable to a complex shallow water environment.Numerical simulations and pool experiments were used to demonstrate the efficiency of this technique.     

支持向量机和遗传算法组合策略的VLCC船中结构优化设计(英文)

In this paper a hybrid process of modeling and optimization,which integrates a support vector machine(SVM) and genetic algorithm(GA),was introduced to reduce the high time cost in structural optimization of ships.SVM,which is rooted in statistical learning theory and an approximate implementation of the method of structural risk minimization,can provide a good generalization performance in metamodeling the input-output relationship of real problems and consequently cuts down on high time cost in the analysis of real problems,such as FEM analysis.The GA,as a powerful optimization technique,possesses remarkable advantages for the problems that can hardly be optimized with common gradient-based optimization methods,which makes it suitable for optimizing models built by SVM.Based on the SVM-GA strategy,optimization of structural scantlings in the midship of a very large crude carrier(VLCC) ship was carried out according to the direct strength assessment method in common structural rules(CSR),which eventually demonstrates the high efficiency of SVM-GA in optimizing the ship structural scantlings under heavy computational complexity.The time cost of this optimization with SVM-GA has been sharply reduced,many more loops have been processed within a small amount of time and the design has been improved remarkably.     

高速铁路系杆拱桥拱肋施工技术

该文以合福铁路铜陵长江大桥北引桥1-96m系杆拱为依托,介绍系杆拱拱肋加工拼装施工工艺,并阐述施工重难点控制要点。     

舰艇主被动声纳方位航迹信息融合研究

介绍了舰艇水声融合系统位置级融合的典型融合技术.重点研究了舰艇水声系统中一部主动声纳和一部被动拖曳线列阵声纳航迹关联的融合,主要是在等样本容量条件下的航迹关联方法,并对融合性能进行了分析.     

双馈调速在泵站系统中的应用研究

双馈调速在泵站上应用是一个全新的应用领域。本文介绍了针对泵站电机和水泵特性的双馈调速系统设计,系统采用按定子磁链定向的矢量控制技术和交-交变频器实现电机转速和功率因数控制,并在泵站现场进行了试验运行。文中给出了试验记录波形及其相关分析。     

基于SVM的隧道衬砌空洞填充物雷达图像识别研究北大核心CSCD

衬砌背后空洞及其填充物对隧道结构安全具有重要影响,开展空洞探测识别对于结构安全评估和病害处置具有重要意义。首先采用室内试验和FDTD正演模拟相结合的方法,获得了空洞内填充空气、水、干砂、湿砂条件下的雷达图谱数据,并对不同填充物波形规律进行对比分析;然后,基于支持向量机算法对波形特征进行提取和分类识别,建立了一种空洞填充物的人工智能辨识方法。研究结果表明,采用傅里叶变换前的平均值、方差、平均绝对离差和傅里叶变换后的最大幅度值max(fft(X))四个统计量作为支持向量机的识别特征,可以有效区分出衬砌背后填充物的六种类型;当采取单一倾向数据时,识别准确率较好,六种物质二分类问题准确率均可以达到90%以上。     

矩形凸台零件加工误差分析

本文根据矩形凸台零件在铣削加工过程中出现的形状误差,指出了该零件数控加工程序编写中存在的问题,并用图解方式阐明了其误差产生的主要原因以及保证零件加工精度的编程要点。     

基于聚类的朴素贝叶斯分类无监督学习方法

为实现朴素贝叶斯分类模型的无监督学习,提出一种基于数据挖掘理论中聚类算法思想的学习方法。该方法首先定义不同类型单维状态分量的差异度量方法和混合型多维向量的联合差异度量方法,通过分析样本数据中向量之间的差异性进行聚类统计,得到研究对象的分类类别,然后对各单维状态分量分别聚类得到特征核值,进而确定不同类别各分量对应单维特征核值空间的概率隶属度。仿真实验结果表明,该方法能有效进行朴素贝叶斯分类学习。     

Investigation of the condition and the behavior of a modular floating structure by harnessing monitoring data

In this paper, the condition and the behavior of an installed and operating Modular Floating Structure (MFS) is investigated and assessed by harnessing field monitoring data and using collectively multiple Correlation Coefficients (CCs) between measured quantities. The examined MFS consists of five pairs of interconnected floating concrete modules and it functions as a floating breakwater. The field monitoring data are acquired through a sensor network deployed on one pair of modules (connected through two groups of connectors) of the MFS. A methodological data processing framework for data organization, manipulation and post-processing is developed and presented. This framework enables the quantification of the structure's condition at different time periods through the calculation of CCs: (a) between the incident wave height and the tensions of the mooring lines and (b) between the tensions of the mooring lines, considering various wave directions. Recorded data at three characteristic time periods during the structure's lifetime are used, namely: (i) before any failure (structure's initial condition), (ii) after the failure of the first connectors' group and (iii) after the failure of the second connectors' group. The data processing framework developed in the present paper is applied to the above recorded data in order to calculate CCs and, therefore, quantify the structure's condition, at the three aforementioned time periods. The quantification of the structure's initial condition resulted to conclusions that were consistent from a physical point of view with the most recently documented, available in-situ mapping of the mooring lines' configuration in the horizontal plane. By considering the structure's initial condition as a reference base for comparison, the effect of the connectors' failure on the CCs, used to quantify this condition, was also investigated and efficiently assessed. Specifically, the significant changes observed in the variation patterns of all examined CCs, when compared with their respective patterns corresponding to the structure's initial condition, demonstrated and confirmed the existence of significant reformation of the examined structural system resulting from the connectors' failure. In this way, the effectiveness of the joint utilization of CCs to assess the structure's condition was proved.